1. Field of the Invention
The invention relates to a method of treating the surfaces of workpieces which are made in particular of metallic or ceramic materials, to a workpiece, mirror, rolling bearing, etc. treated according to such method and a lubricant for running faces of such workpieces, etc.
2. Discussion of the Background
Especially in the automotive and aircraft industry for reducing the fuel consumption efforts are made to manufacture as many components as possible of light metal alloys in order to save weight. During the past few years, considerable pains have been taken to manufacture also parts of internal combustion engines, turbines and the pumps used, for instance fuel pumps, of light metal alloys. When using light metal alloys, particular difficulties arise on wearing faces on which two components are slidingly moved, as this is the case, for instance, with cylinders and pistons of internal combustion engines or with a casing and the rotor of an oil pump supported in said casing, for example of an internal geared wheel pump.
In the case of the steel alloys used for such purposes so far the sections subjected to wear could be protected against premature wear by appropriate surface treatment methods such as case hardening or by applying a wearing layer (Nikasil.RTM.).
With light metal alloys such surface treatment methods are difficult to execute. For instance in DE 195 19 535 A1 a method of machining cylinder running faces of internal combustion engines is suggested in which the wearing faces made of an aluminum silicon alloy are pretreated by a laser in a nitrogen environment so that on the surface of the pretreated workpiece an aluminum nitride layer having a sufficient wear resistance is formed. For such a method considerable apparatus costs are required due to the lasers to be employed and in large-scale production this method is difficult to master so that cheaper solutions are continued to be searched for.
The application of other wearing layers (Nikasil.RTM.) also incurs considerable manufacturing and apparatus costs so that such coatings are used merely in heavy-duty engines, while such solutions are not feasible in large-scale production due to high costs.